Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Wins menores que 0 tiveram qual soma de ano?
 ###Tabelas: CREATE TABLE category_leadership_table (category_leadership_table_id AUTO_INCREMENT PRIMARY KEY, Stage INT, Winner VARCHAR, General classification Żółta koszulka VARCHAR, Mountains classification Klasyfikacja górska VARCHAR, Intermediate Sprints Classification Klasyfikacja najaktywniejszych VARCHAR, Points classification Klasyfikacja punktowa VARCHAR, Teams classification VARCHAR) CREATE TABLE current_clubs_2014_season (current_clubs_2014_season_id AUTO_INCREMENT PRIMARY KEY, Club VARCHAR, Position in 2013 VARCHAR, First season INT, First season of current spell INT, Number of seasons in Superettan INT, Number of seasons in second tier VARCHAR) CREATE TABLE v (v_id AUTO_INCREMENT PRIMARY KEY, Name VARCHAR, Position VARCHAR, Period VARCHAR, Appearances¹ INT, Goals¹ INT, Nationality² VARCHAR) CREATE TABLE motorcycle_grand_prix_results (motorcycle_grand_prix_results_id AUTO_INCREMENT PRIMARY KEY, Year INT, Class VARCHAR, Team VARCHAR, Points INT, Wins INT) CREATE TABLE doubles_6 (doubles_6_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Surface VARCHAR, Partner VARCHAR, Opponent in the final VARCHAR, Score VARCHAR)  
SELECT SUM Year FROM motorcycle_grand_prix_results WHERE Wins < 0